This invention relates to an adjacent station interference rejecting circuit of a radio receiver.
In Japan, AM broadcast stations exist at the frequency spacing of 9 kHz. Therefore, when an interference between broadcast stations occurs in a radio receiver, beat signals whose frequencies are integral multiples of 9 kHz are produced. Of these beat signals, the 9-kHz beat signal actually interfers with the reception. Accordingly, it has been in practice to provide a lowpass filter or a band elimination filter in an audio circuit to remove the interfering beat signal.
However, where such a band attenuation system is used, part of audio signals is attenuated together with the 9-kHz beat signal.